It is known in the art to pultrude various products. Typically rovings made from fiberglass, graphite and/or other known materials are combined with resin with or without matting and following a preshaping step for these materials the entire mass is pulled through a die to form the desired shape. For example only, without limiting the application of the present invention to the window industry, when pultruding sections for window assemblies, doors, patio doors or the like, fiberglass rovings are fed from creels through a resin bath or other known techniques for coating the rovings prior to the preshaper. Matting may also be fed into the preshaper towards the die. At the die, which is normally heated, the product takes its final form exiting from the die in a semi-solid or semi-plastic condition. It is known in the art to use a pulling device to grab or engage a portion of the form being manufactured and thereby provide the pulling force required to move or pull the materials through the die. Normally two pulling devices are used in continuous sequentially alternating pulling and advancing steps to provide for the operation of a continuous process. From time to time the final form exiting the die will tend to bow, sag, or bend in an undesirable direction. This may be caused by the uneven distribution of rovings in the form being manufactured. For example the form may require four upstanding flanges from a base such as is the case in the manufacture of a door sill. In order to manufacture these flanges, extra glass roving loading is required. However the loading of the rovings to one side of the form, for example the top, may result in the bowing of the form upwardly away from the desired path. This bowing over time can cause considerable waste product being manufactured with known processes. Further considerable downtime of the production line may be experienced as the entire process must be cleared and cleaned prior to starting up the process again. Unfortunately it is the nature of the product being formed that causes the well known difficulties in pultruding successfully. Heretofore if any adjustment was to be made in the process to compensate for bowing of the finished product exiting the die, it would be accomplished by loosening the mounting bolts for the head assembly and thereafter jacking or shimming up the head assembly and/or the die. Such coarse adjustments may of course not solve the continuous ongoing problem of bowing of the forms being manufactured. Any lateral adjustments required would further complicate the situation. Other adjustments may be made at the puller by jacking up the puller. An adjustment is made in a direction tending to eliminate the bowing of the form. Often the adjustments are inadequate in spite of the best efforts of the individuals involved.
A problem therefore exists in the art to provide for a pultrusion process and a head assembly therein which recognizes the need to adjust the process from time to time in a predictable manner as forms being manufactured begin to bow, such adjustment being simply and easily carried out by an operator during operation of the pultrusion process, without the need for jacks, fork trucks or the like.
Nowhere within the prior art is there taught a pultrusion process and a method of pultruding including a floating head assembly which provides for means to adjust the process from time to time in a predictable manner as forms being manufactured begin to bow such adjustment being simply and easily carried out by an operator during operation of the pultrusion process.
It is therefore a primary object of this invention to provide a head assembly for a pultrusion process which overcomes the aforementioned problem in the art.
It is a further object of this invention to provide a head assembly for a pultrusion process which floats and is adjustable.
It is a further object of this invention to provide a head assembly for a pultrusion process which floats and is adjustable both laterally and vertically.
It is a further object of this invention to provide a puller assembly which is compatible with a floating adjustable head assembly for a pultrusion process.
It is yet a further object of this invention to provide a pultrusion process and a method therefore which allows for simple adjustment to correct for bowing of the product exiting the die.
Further and other objects of this invention will become apparent to a man skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.